[Bug c/55967] rightshift an unsigned value (X) by it's number of bits does not always yield 0, when X is an unsigned that's leftshifted by it's number of bits and offset

[b1314361 at rmqkr dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55967



JoeSoe <b1314361 at rmqkr dot net> changed:



           What    |Removed                     |Added

----------------------------------------------------------------------------

                 CC|                            |b1314361 at rmqkr dot net



--- Comment #3 from JoeSoe <b1314361 at rmqkr dot net> 2013-01-15 07:15:41 UTC 
---

Hi Jakub Jelinek,



can you elaborate?

What does it mean to say: "The testcase is invalid, the bug is only on the side

of the testcase." ?



Why does gcc not yield the "graceful/expected" result, and why will no effort

be undertaken to make it yield the "graceful/expected" result?



For example: Is it because of optimizations, that would be removed, if it were

to yield the "graceful/expected" result??



In other words: what's the background on this?

Thanks.